In competitive swimming, the rules allow for the athlete to start a race from outside the water from a starting block, which allows for a faster start than from within the water. A starting block is a platform adjacent to the pool, positioned in the center axis of a pool lane, on which a swimmer can stand and jump off. The size, height of the front edge above the water, angle of the platform relative to horizontal and other defining parameters of the platform are specified in the various rule books for swimming.
There are several types of start for a swimmer from the block. One is to have both feet at the leading edge of the block. Another is to have one foot at the leading edge, the other one further back. This start type is called “track start”.
In a track start the swimmer has the toes of the front foot curled around the leading edge and the back foot is set on the starting platform behind the front foot. The starting platform may be inclined to a maximum of 10 degrees to horizontal, as the ruling books state. Therefore most of the horizontal jump force of the back foot, which is desirable for a fast start, is created through friction of the back foot with the starting platform. Although starting platforms are equipped with a surface with a high coefficient of friction, it is desirable to increase said horizontal force by increasing the angle of the surface the back foot touches. The rule books provide for that.
In recent years an invention to improve track starts, described in US patent application US2005/0227813 and international patents such as EP1501609B1, inventor Curry, Francesca, has led to the adding of a second surface to the starting platform in current embodiments of starting blocks.
In a track start, this second surface increases the angle for the back foot by being upwardly inclined with respect to the platform for the swimmer to push against with the backwards foot whilst jumping off from the platform.
The embodiments of said invention place a “foot wedge” such as 5 shown in FIG. 1 at the rear end of the starting block. The distance of this foot wedge from the leading edge is adjustable to support different body sizes and preferences of swimmers.
This adjustability leads to a profile of possible top surfaces 4 in FIG. 1 that a starting block may have as sanctioned by the rule books. In the further description we call this the “sanctioned profile”.
There are several problems with such embodiments, some of them are listed below:
                The foot wedge creates a trip hazard on the top of the starting block, especially for swimmers mounting from a step at the rear. The trip hazard is also present with a step to mount from any side when the wedge is set in a fairly forward position.        In many pools, particularly smaller ones with narrower lanes, the space on the sides is constrained and it is desirable to utilize steps on the back of the block but the trip hazard posed by the foot wedge interferes with this.        In embodiments with a moveable wedge the gap between the wedge and the top of the starting block is not desirable, as it does not support the swimmer's foot in that area.        
The current invention targets to improve one or more of said problems.